docs: def _accumulateFactors(self, aLocation, deltaLocation, limits, axisOnly):
          """
              Calculate the factors of deltaLocation towards aLocation,
          """
          relative = []
          deltaAxis = deltaLocation.isOnAxis()
          if deltaAxis is None:
              relative.append(1)
          elif deltaAxis:
              deltasOnSameAxis = self._axes.get(deltaAxis, [])
              d = ((deltaAxis, 0),)
              if d not in deltasOnSameAxis:
                  deltasOnSameAxis.append(d)
              if len(deltasOnSameAxis) == 1:
                  relative.append(aLocation[deltaAxis] * deltaLocation[deltaAxis])
              else:
                  factor =  self._calcOnAxisFactor(aLocation, deltaAxis, deltasOnSameAxis, deltaLocation)
                  relative.append(factor)
          elif not axisOnly:
              factor = self._calcOffAxisFactor(aLocation, deltaLocation, limits)
              relative.append(factor)
          if not relative:
              return 0
          f = None
          for v in relative:
              if f is None: f = v
              else:
                  f *= v
          return f